Problem: Given the line: $7x + 7y = -21$ What is the $y$ -intercept?
The $y$ -intercept is the point where the line crosses the $y$ -axis. This happens when $x$ is zero. Set $x$ to zero and solve for $y$ $ 7(0) + 7y = -21 $ $7y = -21$ $\dfrac{7y}{7} = \dfrac{-21}{7}$ $y = -3$ The line intersects the $y$ -axis at $(0, -3)$. ${1}$ ${2}$ ${3}$ ${4}$ ${5}$ ${6}$ ${7}$ ${8}$ ${9}$ ${10}$ ${\llap{-}2}$ ${\llap{-}3}$ ${\llap{-}4}$ ${\llap{-}5}$ ${\llap{-}6}$ ${\llap{-}7}$ ${\llap{-}8}$ ${\llap{-}9}$ ${\llap{-}10}$ ${1}$ ${2}$ ${3}$ ${4}$ ${5}$ ${6}$ ${7}$ ${8}$ ${9}$ ${10}$ ${\llap{-}2}$ ${\llap{-}3}$ ${\llap{-}4}$ ${\llap{-}5}$ ${\llap{-}6}$ ${\llap{-}7}$ ${\llap{-}8}$ ${\llap{-}9}$ ${\llap{-}10}$ $(0, -3)$